A device known from German Patent DE-PS 16 21 671 has an extra scarfing nozzle which is arranged on a full width scarfing torch. Either a portion of the surface can be selectively scarfed in addition at the same time with this extra scarfing nozzle which is an advantage, for example, for deeper defects, or only individual defective spots are scarfed by the extra scarfing nozzle. The full width scarfing torch is adjusted in the latter case to a "scarfing value" in such a way that the full width scarfing oxygen stream only sustains one melting bath which makes the scarfing startup for this selective scarfing possible. As a result, metal powder as a startup aid is not necessary.
The use of metal powder as a scarfing startup aid is known. As is evident from German Pat. No. DE-PS 10 16 102, a powder supply apparatus is associated with a scarfing torch consisting of a large number of individual nozzles. This apparatus consists of a supply bin from which the powder arrives at a distributor and which supplies the powder each time to a powder discharge nozzle via several pipelines, in other words, each pipeline is connected to its own nozzle.
A device for scarfing the material surface in accordance with the general type of arrangement with which this invention is concerned is disclosed in German Preliminary Published Application No. 25 53 553. This known device has a wide scarfing oxygen channel and is equipped with an additional nozzle for extra scarfing oxygen as well as with a separately provided powder nozzle.